help me develop a good anti virus program

[sadat2001]

HI there

i am making an boot sector anti virus in C language .
i have almost made it i just want you to go through the algorithm and tell me if there is any error or weakness in my algorithm.

here is my algorithm.

1. got the boot sector by absread() in an array.
2. searched for IO.SYS and MSDOS.SYS in that array.
3. if files found the boot sector is ok.
4. if files not found looked for the non system disk message in that array .
5. if that message is there the disk is non system disk.
6. if the message is not there the disk is infected with the virus.

please help me.
i welcome anu suggestion.

warm regards

sadat